A Comparison of Pharyngeal Swabs and Tracheal Secretions for the Diagnosing of COVID-19

Maibritt Meldgaard Arildsen; Sif Bay Glenting; Anette Marianne Fedder; Bettina Jørgensen; Svend Ellermann-Eriksen; Marianne Kragh Thomsen; Christina Catherine Dahm; Michael Pedersen

doi:10.3390/biomedicines10020488

A Comparison of Pharyngeal Swabs and Tracheal Secretions for the Diagnosing of COVID-19

Biomedicines. 2022 Feb 18;10(2):488. doi: 10.3390/biomedicines10020488.

Authors

Maibritt Meldgaard Arildsen¹, Sif Bay Glenting¹, Anette Marianne Fedder², Bettina Jørgensen³, Svend Ellermann-Eriksen⁴, Marianne Kragh Thomsen⁴, Christina Catherine Dahm⁵, Michael Pedersen¹

Affiliations

¹ Comparative Medicine Lab, Department of Clinical Medicine, Aarhus University, 8200 Aarhus, Denmark.
² Emergency Department, Aarhus University Hospital, 8200 Aarhus, Denmark.
³ Department of Renal Medicine, Aarhus University Hospital, 8200 Aarhus, Denmark.
⁴ Department of Clinical Microbiology, Aarhus University Hospital, 8200 Aarhus, Denmark.
⁵ Research Unit for Epidemiology, Department of Public Health, Aarhus University, 8000 Aarhus, Denmark.

Abstract

The aim of this study was to compare the test results from patients who, within a short timescale, have been tested for COVID-19 using both a pharyngeal swab and tracheal secretion. Data were collected from the database of AUH, from patients hospitalized between 1 March 2020 and 1 March 2021 who, due to symptoms of COVID-19, were tested by a pharyngeal swab and by tracheal secretion. We found great agreement between oropharyngeal swab and tracheal secretion RT-PCR testing for the diagnosis of COVID-19, with 98.5% of double tests being concordant and only 1.5% being discordant. This finding may advocate a single-test strategy being either an oropharyngeal swab RT-PCR testing or tracheal secretion, although this study revealed 15.9% false negative oropharyngeal swabs.

Keywords: COVID-19; SARS-CoV-2; comparison; pharyngeal swab; test methods; tracheal suction.